This invention relates to an antifriction bearing for supporting machine elements so as to be longitudinally moveable, and including at least one endless row of rolling elements. Each rolling-element row is arranged so that the rolling elements enter and leave a load zone between a race of the guide block and a race of the associated machine element. The direction of travel of the elements is reversed in the reversing tracks of end sections disposed at both the entry and exit ends of the load zone, the rolling elements are returned in a return track interconnecting the reversing tracks of the two end sections.
In a known antifriction bearing of this type, the end sections are made of an elastic plastic in order that the rolling elements may enter and leave the reversing track of the end sections without jolts. This jolting results in undesirable rapid wear in use, since the entry and exit edges of the reversing track necessarily consist of a relatively soft and delicate plastic. As a result, play develops between the load zone and the entry or exit edge of the reversing tracks even after a short period of use, and this play impairs the precise guidance of the rolling elements and may lead to deleterious jamming and skewing of the rolling elements in the bearing. In addition, due to the inadequate guidance of the rolling elements in the area between the load zone and the entry or exit edge of the reversing tracks, undesired entering and leaving jolts occur which produce objectionable running noise.
Another antifriction bearing of this type is known in which the end sections are made of wear-resistant steel. In this case the rolling elements are guided along relatively hard, unyielding edges and walls of the reversing track so that the rolling elements enter and leave the reversing track of the end section with a jolt and the antifriction bearing is noisy in operation. Moreover, the reversing track and the rolling elements are damaged by the resultant severe undamped impact and guidance shocks in the reversing track.
The present invention is therefore directed to the provision of an improved antifriction bearing of the type mentioned above in which the rolling elements enter and leave and are guided in the reversing track smoothly and without jolts, and in which the rolling elements are at the same time guided in the reversing track in such a way that there is no wear. In addition, the antifriction bearing of the invention can be manufactured economically.